In the metal working industry there are a large number of transfer feed presses which vary in size and output depending upon a manufacturer's specific needs. The larger presses, for example, may have a capacity of approximately 600 tons to 3000 tons with a stroke rate of perhaps 15 to 30 press strokes per minute. Such a transfer feed press is capable of a wide range of press operations which virtually eliminate the requirement of using several presses to manufacture a part. The cost efficiency of using a large transfer feed press increases dramatically with an increase in the number of parts to be produced during a specific production run. Moreover, the cost efficiency is also increased when a single transfer feed press can perform most or all of the press operations without transferring the workpieces to multiple presses. For these reasons, it is essential that a transfer feed press be able to move the workpieces in the press to the various die stations rapidly, accurately and efficiently.
Once the workpiece is mounted in a finger unit in transfer feed press, it may be moved any number of times to align it with the various die stations in the press. As an example, a workpiece may have to be rotated 180.degree. for a piercing operation, then rotated back 180.degree. for a trimming operation, or some other press operation. This procedure may occur any number of times before the part is transformed into a finished product. A workpiece such as an automotive suspension arm may be transferred between blank, draw, restrike, trim and pierce, flange and coin, cam pierce, and cam extrude stations in a typical sequence of steps performed by a transfer feed press. Regardless of the number of operations performed, the workpieces must be positioned rapidly and accurately in a cost efficient manner.